. >> i'm dana king. shut down for hours because of a power outage. liz. >> reporter: dana, between 40 and 50,000 commuters were effected by the massive melt down this evening. look behind me. as you said all under ground transit stations shut down tonight. many are still trying to figure out how to get home. the chaos began with a grew some accident earlier this evening. >> i seen her. when the trollly went back i didn't see her. >> a woman in a wheelchair clipped the backside of a westbound trollly and was dragged underneath the car along market from delores to church street. >> the woman was taken to sf general for life-threatening injuries. the accident shut down service from the f trolly. 45 minutes later another melt down. this time the transformer that gives power to all the under ground lines blew up. shutting down service to the entire under ground transit. apparently it was damaged with water damage from yesterday. >> the massive shut down forced thousands of passengers to find another way home. >> computers were down in the subway. we waite